With the aim of upgrading the power conversion efficiency of organic solar cells (OSCs), four novel non-fullerene, A 1 −A 2 −D−A 2 −A 1 -type small molecules were designed that are derivatives of a recently synthesized molecule SBDT-BDD reported for its efficient properties in all-small-molecule OSCs (ASM-OSCs). Optoelectronic properties of the designed molecules were theoretically computed with a selected CAM-B3LYP functional accompanied by the 6-31G(d,p) basis set of density functional theory (DFT), and excited-state calculations were performed through the time-dependent self-consistent field. The parameters of all analyzed molecules describing the charge distribution (frontier molecular orbitals, density of states, molecular electrostatic potential), absorption properties (UV−vis absorption spectra), exciton dynamics (transition density matrix), electron−hole mobilities (reorganization energies), and exciton binding energies were computed and compared. All the designed molecules were found to be superior regarding the aforesaid properties to the reference molecule. Among all molecules, SBDT1 has the smallest band gap (3.88 eV) and the highest absorption maxima with broad absorption in the visible region. SBDT3 has the lowest binding energy (1.51 eV in chloroform solvent) ensuring easier and faster dissociation of excitons to produce free charge-carriers and has the highest open-circuit voltage (2.46 eV) with PC 61 BM as the acceptor. SBDT1 possesses the highest hole mobility because it has the lowest value of λ + (0.0148 eV), and SBDT4 exhibits the highest electron mobility because it has the lowest value of λ − (0.0146 eV). All the designed molecules are good candidates for ASM-OSCs owing to their superior and optimized properties.

BACKGROUND: Dementia is a common form of Alzheimer disease which is affecting the quality of older adults' life. Non-drug treatment such as cognitive therapies are more beneficial for such patients. These days, mobile applications are providing tremendous opportunities for aiding the medicinal treatment. OBJECTIVES: This paper presents CareDa mobile application based solution for dementia patients and their caregivers. Unlike, other available mobile applications, CareD provide a single resolution for maximum dementia related complications. The main objective of this application is to improve the quality of life of dementia patients and facilitate their caregivers. CareD also aims at providing native language support i.e. Urdu to the people of Pakistan. METHODS: CareD comprises of various modules including cognitive therapy sessions, patient tracking, reminders, healthy living to aid dementia patients in their everyday activities. Experimental study involving dementia patients and their caregivers has been carried out to evaluate the usability and effectiveness of this application. RESULTS: Twenty patients were included in the study. Results showed that CareD is very effective and helpful in decreasing the disease progression as well as in relieving the burden of caregivers. CONCLUSION: CareD has been found to be a useful and efficient solution for dementia patients. It was observed that utilization of mobile application was progressively successful in reducing the stress of both; patients and their caregivers. The use of native language Urdu made the application more learnable for older adults and improved its acceptance.

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LEDs have been fabricated from erbium-doped Si and Si 1−x Ge x quantum wells, and exhibit radiation at 1.54 µm when operated in forward bias. The strained Si 1−x Ge x /Si quantum wells were doped with erbium, either by implantation or during MBE growth, for two germanium fractions, 13% and 25% respectively, and their quality was monitored by transmission electron microscopy. PL measurements as a function of temperature exhibit a dependence of the high temperature signal quenching on the germanium fraction. The forward-bias EL and PL from the Er:Si 1−x Ge x , exhibit different emission energies irrespective of whether the samples are ion implanted or doped during MBE growth. The energy changes are attributed to confinement of injected holes in the electroluminescence measurement by the quantum wells, and subsequent excitation of a different set of Er atoms which may be in the Si 1−x Ge x host. Electric field effects have been eliminated by performing the EL and PL under identical conditions. This is very encouraging for the potential use of SiGe waveguides in future injection-type silicon-based LEDs.